Question

What is The factor to this problem?

A.(x+2)(x-9)
B.(x-3)(x-6)
C.(x-2)(x+9)
D.(x+18)(x-1)

Answer 1

C

Explanation:

You know that one term has to be negative and the other has to be positive because -18 is negative (neg * pos = neg). You also know that the two terms have to sum up to 7! 9 and -2 fit the bill.

If you're not sure, you could always expand and check.

(x-2)(x+9)

x^2 -2x + 9x -18

x^2 +7x -18 (or, in this case, +7b)

Hope that helps!